Solid Oxide Fuel Cells contain Ni-based anodes which are sensitive to sulfur poisoning and or carbon based degradation. Infiltration of the anode with materials that allow the anode to be more robust to these poisons is a known prior art strategy for improving robustness of cells. Such infiltration is best performed with the nickel in the anodes in a reduced, metallic state.
A drawback of prior art strategies and methods for infiltration is that the anode needs to have more porosity in the oxidized cell which reduces strength of the anode. If the cell is reduced and then infiltration is done prior to fabrication of the stack, keeping the cell reduced during stack fabrication is a problem because air can be useful in the sealing process, especially when using sintered glass seals.
On the other hand, it is very difficult to first reduce a cell, then infiltrate the anode, and then re-oxidize the cell before fabricating a stack, without causing the cell to crack.
What is needed in the art is an improved process for infiltrating an SOFC anode to at least partially protect the anode from exogenous poisons.
It is a principal object of the present invention to infiltrate all the SOFC anodes in an SOFC stack without causing any of the cells to subsequently crack.